1. Field of the Invention
The present invention generally relates to substrates having leads, and more particularly to a substrate having a conductor pattern and leads connected thereto, that is suited for receiving a target object having terminals or pads to be electrically connected to the leads.
2. Description of the Related Art
FIG. 1 is a cross sectional view of an example of a conventional substrate having leads. A substrate 200 illustrated in FIG. 1 includes a housing 201 and leads (or connection terminals) 202. Only one lead 202 is visible in the cross sectional view of FIG. 1. The lead 202 is fixed within a through hole 213 of the housing 201.
The lead 202 includes connection parts 215 and 216, and a spring part 217. The connection part 215 is integrally formed on a portion of the spring part 217 that projects from an upper surface 201A of the housing 201. The connection part 215 is pushed by a pad 206 of a target object 205, such as a wiring board, and achieves electrical contact between the lead 202 and the target object 205 through contact between the connection part 215 and a surface 206A of the pad 206.
On the other hand, the connection part 216 is exposed at a lower surface 201B of the housing 201. The connection part 216 is electrically connected to a circuit board 209, such as a mother board, through an external contact part 208. Hence, the lead 202 is electrically connected to both the target object 205 and the circuit board 209.
The spring part 217 is accommodated within the through hole 213, but a portion of the spring part 217 projects from the upper surface 201A of the housing 201 as described above. Hence, when the pad 206 pushes against the connection part 215, the connection part 215 mainly slides along the surface 206A of the pad 206. An example of such a structure is proposed in a U.S. Pat. No. 7,264,486.
However, a sliding displacement of the connection part 215 along the surface 206A of the pad 206 is relatively large when the pad 206 pushes against the connection part 215. For this reason, a width of the pad 206 along a direction in which the connection part 215 slides along the surface 206A thereof needs to be relatively wide, and there was a problem in that the pads 206 provided on the target object 205 cannot be arranged at a relatively narrow pitch.